1. Field of the Invention
The present invention relates to an applicator including writing and marking instruments such as line markers, felt pens, fountain pens and ball-point pens, and more particularly relates to an applicator that comprises a cylindrical body whose open end is closed with a plug such as an end closure.
2. Description of Related Art
Most of the line markers and the like applicators have been of the disposable type to be discarded when their ink was consumed almost completely, regardless of their bodies being reusable. Therefore, some users have wanted or tried to refill such line markers or the like with a fresh amount of ink so as to use them again. Certain proposals made in view of this demand relate to applicators of an improved structure such that an end closure (also called xe2x80x9ca proximal plugxe2x80x9d) is capable of disengagement from the cylindrical body when refilling the applicator with the ink.
The Japanese Patent Laying-Open Gazette No. 2001-105781 discloses an example of such an improved structure, wherein a deep groove is formed between an end of a cylindrical body and a penpoint holder or a proximal plug. A coin or the like hand tool can be inserted easily into this groove when the plug is to be taken off.
Thus, the above-described art applicators have necessitated coins or the like tools in removing their plugs from cylindrical bodies. Further, a lever action generated by such an operation has caused a strong stress to permanently deform the plug or an end portion of the cylindrical body adjacent to the groove. Repeated detachment of a plug will deteriorate such end portions more and more, until making it impossible to mount again the plug on the cylindrical body or making its reattached plug very prone to slip off.
An object of the present invention is therefore to provide such an applicator that its plug can readily be taken off its cylindrical body, without need of any handy tool such as a coin. The improvement has to be designed herein such that the plug is capable of repeated detachment and reattachment operations, while being protected from any serious permanent deformation and any inadvertent slipping off. In this specification, a plug can be a unitary member or can be made up of a plurality of parts.
In a first mode of the invention made to achieve this object, the applicator may comprise a cylindrical body to be filled with a liquid for application, and a plug that may be either or both of distal and proximal plugs. The plug, that may be exemplified herein as the proximal plug, is detachably attached to an open end of the applicator""s cylindrical body and exposed in part to the outside. Characteristically to the present applicator, its plug may have at least one slot formed therein and extending axially of its cylindrical body such that the exposed part of the plug can be pinched centripetally to cause its elastic and temporary deformation. Owing to this feature, an inner region of the plug in a pressed contact with the cylindrical body will be forced to reduce its overall radius of curvature to thereby enable and facilitate removal of the plug.
Such a longitudinal slot or slots will render the applicator""s plug ready to be distorted. If the exposed portion of the plug is pinched in a centripetal direction, then the slot or slots will permit this portion to distort itself by a distance corresponding to the width of each slot. An elastic decrease in overall diameter of the plug is thus caused in the centripetal direction, thereby producing a sufficient annular gap between the cylindrical body and the plug fitted therein, or at least weakening a contact pressure between them to such an extent as making it easy to detach the plug.
In this mode of carrying out the present invention, users of this applicator need not to use any tool or coin when they repeat to attach and detach the plug, and what is more surprising, it will never slip off inadvertently during usage or storage of this applicator. The slots may not necessarily have a uniform width between their longitudinal ends, but may each be of a varying width (as in V-shaped slots).
In a second mode of the present invention, the applicator may comprise a cylindrical body to be filled with a liquid for application, and a plug selected from the group consisting of distal and proximal plugs. The plug is detachably attached to an open end or ends of said body and exposed in part to the outside. Characteristically to this applicator, its plug may have at least one flexible portion extending axially of its cylindrical body such that the exposed part of the plug can be pinched centripetally to cause elastic and temporary deformation thereof Owing to this feature, an inner region of the plug in a pressed contact with the cylindrical body will also reduce its overall radius of curvature to facilitate removal of the plug from this body.
The term xe2x80x98flexible portion or portionsxe2x80x99 as used herein, means a flexible portion that is more subject to elastic distortion than other areas adjoining to or surrounding the flexible portion by reason of at least one of a) the flexible portion having a thickness, with the thickness of the flexible portion being decreased compared to the thickness of other areas adjoining to or surrounding the flexible portion and b) the flexible portion being formed of a softer material than the material defining the other areas adjoining to or surrounding the flexible portion.
Such longitudinal flexible portions will render the applicator""s plug ready to be distorted similarly to the applicator in the first mode of the invention. If the exposed portion of the plug is pinched in a centripetal direction, then the flexible portion or portions will permit the exposed portion to distort itself by a distance corresponding to the width of each flexible portion. An elastic decrease in overall diameter of the plug is thus caused in the centripetal direction, thereby producing a sufficient annular gap between the cylindrical body and the plug fitted therein, or at least weakening a contact pressure between them to such an extent as making it easy to detach the plug.
Preferably, the plug may be a proximal plug, and one of this plug and the cylindrical body has a protrusion formed integral therewith and at a portion contacting the mating body or plug. Correspondingly, the other of the cylindrical body and the proximal plug has an engageable portion that is a lug or a recess facing such a protrusion. Each longitudinal slot or flexible portion extends over and beyond the protrusion or engageable portion.
With the plug being fitted in the cylindrical body, the protrusion will be kept in engagement with the recess or lug, that is the engageable portion, so as to inhibit the plug from slipping off said body during normal use of the applicator. Since the plug has longitudinal slots formed therein and extending beyond the protrusion or engageable portion, the region where such a protrusion or portion is located will also show a significant decrease in overall diameter when the exposed region of plug is pinched centripetally. Thus, disengagement of said protrusion from said engageable portion is facilitated to enable smooth detachment of the plug from the applicator body.
Also preferably, each slot has an end opened in the exposed end face of the plug. This exposed end is a rear end of the plug if it is a proximal plug, or a fore end of the plug if it is a distal plug, and in any case, being its outer end remote from a middle region of this applicator.
By virtue of the slot or slots having their end or ends opened in the exposed end face of the plug in the described example, the plug will stand in part in a cantilevered state easy to show distortion and consequently ready removal from the cylindrical body.
Alternatively, the longitudinal slot or slots may be disposed in a middle region of the plug so that it has or they have opposite closed ends.
Even in this case, the plug""s middle region is flexible enough, as compared with a middle region devoid of such slots.
Preferably, the slot or slots may be formed in a peripheral wall of the plug and this wall defines therein a central cavity.
The central cavity will permit centripetal displacement of portions of the peripheral wall when it elastically deforms itself, thus further rendering the plug easy to to be distorted and removed.
Also preferably, two or more such longitudinal slots are formed in the plug, and at least one tying slot bridges the two adjacent longitudinal slots.
In this case, peripheral wall regions of the plug, that are almost surrounded each by such longitudinal and tying slots, are in a cantilevered state to be easier to be distorted.
It may be more preferable that the two or more longitudinal slots are connected one to another by at least one tying slot continuing from one end of the two adjacent longitudinal slots.
Also in this case, the longitudinal slots having one end connected to each other by the tying slot will elongate in an axial direction the cantilevered peripheral wall regions, thus making flexible deformation (viz., distortion) thereof easier.
It also is preferable that two or more longitudinal slots are formed and at least two of them have inner ends and closed outer ends, with the xe2x80x98inner endsxe2x80x99 being connected one to another by a tying slot. This inner end is a fore end of the plug if it is a proximal plug, or a rear end of the plug if it is a distal plug. In other words, the inner end is located nearer or closer to the applicator""s middle height in the drawings than an xe2x80x98outer endxe2x80x99 is.
In this case, the at least two longitudinal slots having the closed ends in addition to the inner ends connected to each other by the tying slot will provide a tongue-like cantilevered wall region. Outer end face portions of the peripheral wall close the slots"" outer ends so as to serve as fulcrum-like supports for each tongue-like region, thereby rendering flexible deformation (viz., distortion) thereof much easier and smoother.
The plug in this applicator may further have one cutout or more cutouts each in communication with the one or more of the slots.
Such a cutout or cutouts noticeably shortens or shorten the boundary between the remainder of the peripheral wall and each tongue-like region surrounded thereby. These cutouts, that may preferably be slots convenient to manufacture, will also enhance capability of flexible deformation (viz., distortion) of surrounded cantilevered regions.
It also is preferred herein that the plug of the applicator is a double-cylinder composed of an inner tube coaxially enclosed with an outer tube, wherein the slots or the flexible portions are formed in the outer tube.
The plug in this case is designed such that only the outer tube is subjected to radial shrinkage. This structure will be advantageous in that the plug can be taken off the cylindrical body more lightly.
Preferably, the plug may have on its outer periphery an airtight region, which will be kept in close contact with the inner periphery of the cylindrical body.
Such an airtight region will prevent the ink or the like application liquid from leaking out through the plug, and thus protect the ink from drying up.
The outer tube of the plug may have a further region formed at least in part integral with a plurality of annular ribs. This region is located on an outside of the airtight region.
These ribs overlying one another and surrounding the outer tube are intended to protect the user""s fingers from sliding over the outer periphery of plug.
In an embodiment of the present invention, the applicator comprises a cylindrical body to be filled with a liquid for application, and a plug consisting of at least one of distal and proximal plugs, the plug detachably attached to an open end or ends of said body and exposed in part to the outside. Characteristically to this embodiment, the plug is composed of an outer tube and an inner tube disposed therein and has at least one longitudinal slot formed in the outer tube and extending axially of the cylindrical body, each slot being opened in the outer exposed face of the plug. Either the plug or the cylindrical body has a protrusion formed integral therewith and at a portion contacting the mating body or plug, and correspondingly, the cylindrical body or the plug has an engageable portion that is a lug or a recess facing such a protrusion. Each longitudinal slot extends over and beyond the protrusion or engageable portion such that the exposed part of the plug can be pinched centripetally to thereby cause elastic and temporary deformation of the plug so that an inner region of the plug in a pressed contact with the cylindrical body will be forced to reduce its overall radius of curvature to thereby enable and facilitate removal of the plug from this body. The plug in this embodiment has on its outer periphery an airtight region to be brought into a close contact with the inner periphery of the cylindrical body, when fitted therein.
It is preferable in this embodiment that the number of the slots is at least two and each slot has an inner end continuing to an extension lying along the peripheral circumference of the outer tube.
In this type of the applicator, each portion almost surrounded by the slots and extension is adjoined by a shortened boundary to the neighboring portion and is therefore easier to distort.
Also preferably, each slot has an inner end continuing to extensions formed along the peripheral circumference of the outer tube, thereby assuming a T-shape as a whole.
In another embodiment, the applicator comprises a cylindrical body to be filled with a liquid for application, and a plug consisting of at least one of distal and proximal plugs, the plug detachably attached to an open end or ends of said body and exposed in part to the outside. Characteristically to this embodiment, the plug is composed of an outer tube and an inner tube disposed therein and has at least two longitudinal slots formed in the outer tube and extending axially of the cylindrical body, wherein the at least two of the slots have outer ends closed and inner ends connected one to another by a tying slot. Either such a plug or the cylindrical body has a protrusion formed integral therewith and at a portion contacting the mating body or plug, and correspondingly, the cylindrical body or the plug has an engageable portion that is a lug or a recess facing such a protrusion. Each longitudinal slot extends over and beyond the protrusion or engageable portion such that the exposed part of the plug can be pinched centripetally to thereby cause elastic and temporary deformation of the plug so that an inner region of the plug in a pressed contact with the cylindrical body will be forced to reduce its overall radius of curvature to thereby enable and facilitate removal of the plug from this body. The plug in this embodiment also has on its outer periphery an airtight region to be brought into a close contact with the inner periphery of the cylindrical body, when fitted therein.
It is desirable that the number of such longitudinal slots is an even number so that one or more pairs of them are provided, and the two slots forming one pair have the inner ends communicating one with another through the tying slot. These three slots constitute as a whole a generally U-shaped composite slot, which defines therein a tongue-shaped region.
A basal outer end of such a tongue-shaped region will serve as a fulcrum-like support rendering this region more easy to elastically deform (viz., distort) itself.
More preferably, the number of such longitudinal slots is four so that there are provided a first slot, a second slot, a third slot and a fourth slot. The first and second slots form a first pair, with the third and fourth slots forming a second pair. The two slots forming each pair have their inner ends communicating one with another through the tying slot. These three slots constitute as a whole a generally U-shaped composite slot, which defines therein a tongue-shaped region.
The user will be able to lightly and readily disengage the plug from the cylindrical body of applicator, because he or she need to just pinch the plug at its two tongue-shaped regions that preferably face one another in a diametric direction. Although two pairs of such tongue-shaped regions facing one another may be provided (by forming eight slots), one pair of them suffice well for the plug to be manufactured as simply as possible.